"Butterflies must brush questions" and "Yuan Teng basic questions". The materials that can be purchased for poor math foundation in senior high school include "Butterflies Must Brush Questions" and "Yuan Teng Basic Questions". These books are very suitable for students with weak mathematical foundation, pay attention to the foundation, have appropriate promotion, and can enhance students' learning ability. The content is comprehensive and the appearance is beautiful, which is suitable for students to brush questions.